VISHAY SEMICONDUCTORS
Optical Sensors
Application Note
Designing the VEML6075 into an Application
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Revision: 08-Sep-16
1
Document Number: 84339
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APPLICATION NOTE
By Reinhard Schaar
UVA / UVB LIGHT SENSOR WITH I
2
C INTERFACE
The VEML6075 is an advanced ultraviolet (UVA / UVB) light sensor with an I
2
C protocol interface and designed in the
CMOS process.
An accurate VEML6075 UVI sensing system requires visible and infrared noise compensation and a teflon diffusor for cosine
angular response correction. The UVI formulas and related UVI formula coefficients are discussed here in detail. The coefficient
extraction method and a calculated example are also presented in this application note.
Fig. 1 - Block Diagram of the VEML6075
The VEML6075 is easily operated via a simple I
2
C command. It incorporates a photodiode, amplifiers, and analog / digital
circuits into a single chip. The VEML6075’s adoption of Filtron
TM
UV technology provides the best spectral sensitivity to cover
UVA and UVB spectrum sensing. It has excellent temperature compensation and a robust refresh rate setting without the need
for an external RC low-pass filter.
The VEML6075 shows linear sensitivity to solar UVA as well as UVB light and its sensitivity can easily be adjusted with selecting
the proper integration times.
The device can be used as a solar UV indicator for cosmetic / outdoor sport handheld products or any kind of consumer
products.
The VEML6075 comes within a very small surface-mount package with dimensions of just 2.0 mm x 1.25 mm x 1.0 mm
(L x W x H).
The VEML6075 operates within a supply voltage range from 1.7 V to 3.6 V. The necessary pull-up resistors at the I
2
C line can
be connected to the same supply as the micro controller is connected to, between 1.7 V and 3.6 V.
4
3SDA
GND
VEML6075
State machine
I
2
C interface
UV-PD
Oscillator
Timing
controller
V
DD
1
2
V
DD
SCL
